Spike in dengue cases expected in Thailand in 2016, expert says

BANGKOK (Thomson Reuters Foundation) - The number of dengue cases in Thailand is expected to spike this year, a researcher said, as experts from across Asia met to discuss introduction of the first ever dengue vaccine to control and prevent the disease.

An anti-government protester carries out fumigation to prevent the spread of dengue fever during a rally near the Government Complex in Bangkok February 16, 2014. REUTERS/Chaiwat Subprasom

Dengue - which causes flu-like symptoms and can develop into the deadly dengue hemorrhagic fever - is the world’s fastest-spreading tropical disease, with the annual number of cases increasing 30-fold in the last 50 years, according to the World Health Organization (WHO).

The disease is endemic in 128 countries - compared with nine countries experiencing severe dengue epidemics prior to 1970. Asia has the most cases, with 67 million people infected per year, researchers say.

In Thailand, the 2016 caseload may be on par with the last big outbreak in 1987, when there were about 170,000 cases, said Dr. Usa Thisyakorn, professor of pediatrics at Chulalongkorn University in Bangkok and chairwoman of Asian Dengue Vaccination Advocacy (ADVA).

“We have had a lot of patients in this season. It’s a big predictor that we’ll have a big problem with dengue this year. If even in the cool season we have dengue, then it will be worse in the following year” in the hot and rainy seasons, Usa said on the sidelines of the Asia Dengue Summit organized by ADVA.

“It is quite, quite bad. Last year, in 2015, we had 140,000 cases. We predict that this year, we will also have a bad season,” said Usa, speaking late on Wednesday.

At the two-day summit in Bangkok, which ends on Thursday, scientists, doctors and government officials are trying to identify the best way to use French drugmaker Sanofi’s dengue vaccine Dengvaxia and other control and prevention tools currently under development.

MILESTONE YEAR

Experts described 2015 as a milestone year, with Dengvaxia being approved last month in Mexico, the Philippines and Brazil.

“We’ve been working on dengue vaccines for 70 years, and now we have a license for a vaccine,” said Duane Gubler of the Duke-National University Singapore Graduate Medical School.

Gubler and other experts welcomed the new vaccine even if it was “not perfect” and did not protect equally against the four different serotypes of dengue. They also said the vaccine alone would not be enough to stamp out dengue.

“The perfect vaccine would give equal protection to all serotypes,” Gubler said on Wednesday.

“We have a whole host of dengue control tools in the pipeline that can be integrated with the vaccine,” he added. “We’ll have to integrate it (the vaccine) with vector-control methods. This meeting is to get the public health community on board in endemic countries.”

There is no dedicated treatment for dengue, also known as breakbone fever, and patients are generally asked to rest, drink plenty of fluids and take medication to bring down fever and reduce joint pains.

Scientists are developing antiviral drugs to inhibit virus replication in humans, in addition to vaccines.

They are also working on genetic modification to control the mosquito population, and introducing bacteria that blocks the dengue virus within mosquitoes, said Dr. Raman Velayudhan, WHO coordinator for the dengue and vector ecology and management unit.